Very large and very small numbers are hard to read and easy to miscopy in ordinary form. Scientific notation compresses them into a short coefficient and a power of ten — 93,000,000 becomes 9.3 × 10⁷ and 0.00004506 becomes 4.506 × 10⁻⁵. This converter accepts a number in any common format and shows it in all of them at once: scientific notation, the E-notation calculators print, engineering notation with its SI prefix, and the full decimal.
How to use the scientific notation converter
- Type a number. Plain decimals (
0.00004506,93,000,000), E-notation (6.02e23) and written scientific notation (4.5 × 10^-6) are all accepted. - Keep all digits or round to a set number of significant figures.
- The tape shows the scientific form, E-notation, engineering notation, the SI-prefix equivalent and the standard decimal. The steps explain how far the decimal point moved and why the exponent has its sign.
Converting by hand
- Place the decimal point after the first non-zero digit.
- Count how many places it moved.
- If it moved left (the number is 10 or more), the exponent is positive. If it moved right (the number is less than 1), the exponent is negative.
93,000,000: the point moves 7 places left → 9.3 × 10⁷
0.00004506: the point moves 5 places right → 4.506 × 10⁻⁵
5.5: already between 1 and 10 → 5.5 × 10⁰
Four notations compared
| Notation | 0.00004506 | 93,000,000 |
|---|---|---|
| Scientific | 4.506 × 10⁻⁵ | 9.3 × 10⁷ |
| E-notation | 4.506E-5 | 9.3E+7 |
| Engineering | 45.06 × 10⁻⁶ | 93 × 10⁶ |
| SI prefix | 45.06 µ (micro) | 93 M (mega) |
Engineering notation is common in electronics and physics because it lines up with metric prefixes: a 0.000000047 F capacitor is written 47 × 10⁻⁹ F, or 47 nF.
SI prefixes
| Prefix | Symbol | Power of ten |
|---|---|---|
| tera | T | 10¹² |
| giga | G | 10⁹ |
| mega | M | 10⁶ |
| kilo | k | 10³ |
| milli | m | 10⁻³ |
| micro | µ | 10⁻⁶ |
| nano | n | 10⁻⁹ |
| pico | p | 10⁻¹² |
The International Bureau of Weights and Measures (BIPM) maintains the official list, which since 2022 runs from quecto (10⁻³⁰) to quetta (10³⁰).
Scale of the universe in scientific notation
| Quantity | Value |
|---|---|
| Diameter of a hydrogen atom | about 1 × 10⁻¹⁰ m |
| Width of a human hair | about 7 × 10⁻⁵ m |
| Earth–Sun distance | 1.496 × 10¹¹ m |
| Avogadro constant | 6.022 140 76 × 10²³ per mole (exact) |
| Stars in the Milky Way | roughly 1 × 10¹¹ to 4 × 10¹¹ |
Precision and trailing zeros
Writing 93,000,000 hides how precise the figure is. As 9.3 × 10⁷ it clearly has two significant figures; as 9.300 × 10⁷ it has four. Use the rounding menu to present a value with the precision you intend, or the significant figures rounding calculator for a fuller explanation.
To add, subtract, multiply or divide numbers that are already in this form, switch to the scientific notation calculator. If your course calls a × 10ⁿ “standard form” (as UK schools do), the standard form calculator covers both meanings of the term.
Frequently asked questions
How do I convert a number to scientific notation?
Move the decimal point until exactly one non-zero digit is in front of it, then count the moves. Moving left gives a positive exponent and moving right gives a negative one. 0.00004506 needs 5 moves to the right, so it is 4.506 × 10⁻⁵.
What is E-notation?
A typed form of scientific notation used by calculators, spreadsheets and programming languages. The letter E means "times ten to the power of", so 4.506E-5 is 4.506 × 10⁻⁵ and 6.02E23 is 6.02 × 10²³.
What is engineering notation?
Like scientific notation, but the exponent is always a multiple of 3, so the coefficient is between 1 and 1,000. That matches SI prefixes: 45.06 × 10⁻⁶ meters is 45.06 micrometers (µm).
How do I convert scientific notation back to a regular number?
Move the decimal point by the exponent: right for a positive exponent, left for a negative one, filling gaps with zeros. 9.3 × 10⁷ becomes 93,000,000.
How many significant figures does a number in scientific notation have?
Every digit in the coefficient. 6.0 × 10²³ has two significant figures and 6.022 × 10²³ has four, which is one reason scientists prefer this notation.